Add javadocs to the isStopAction methods

src/com/adam/aslfms/receiver/BuiltInMusicAppReceiver.java

@@ -60,6 +60,14 @@ public BuiltInMusicAppReceiver(String stopAction, String appPackage,
 		app_name = appName;
 	}
 
+	/**
+	 * Depending on the action received decide whether it should signal a stop or not.
+	 * By default, it compares it to the unique `this.stop_action`, but there might be
+	 * multiple actions that cause a stop signal.
+	 * 
+	 * @param action	the received action
+	 * @return			true when the received action is a stop action, false otherwise
+	 */
 	protected boolean isStopAction(String action) {
 		return action.equals(stop_action);
 	}

src/com/adam/aslfms/receiver/SEMCMusicReceiver.java

@@ -18,6 +18,14 @@ public SEMCMusicReceiver() {
 	}
 
 	@Override
+	/**
+	 * Checks that the action received is either the one used in the
+	 * newer Sony Xperia devices or that of the previous versions
+	 * of the app.
+	 * 
+	 * @param action	the received action
+	 * @return			true when the received action is a stop action, false otherwise
+	 */
 	protected boolean isStopAction(String action) {
 		return action.equals(ACTION_SEMC_STOP) || action.equals(ACTION_SEMC_STOP_LEGACY);
 	}